CVE-2026-63639 — Valkey: UAF in stream deserialization may lead to remote code execution
Valkey is a distributed key-value database. Prior to 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1, Valkey's RESTORE command accepts a malformed RDB stream payload that assigns one Pending Entry List NACK to multiple consumers during stream consumer-group deserialization, causing a use-after-free when one consumer is deleted while another still references the shared NACK and potentially allowing remote code execution. This issue is fixed in versions 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 1.2% (30-day exploitation probability)+10
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Valkey-io Valkey).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.8 | CVSS 3.1 | High | 2.8 | 5.9 | security-advisories@github.com via NIST National Vulnerability Database |
| 8.8 | CVSS 3.1 | High | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · valkey-io/valkey
- SSVC assessment updated
- Record published
- CVSS changed · 8.8
- Source status changed · → Awaiting Analysis
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
12 on the record
- github.com/valkey-io/valkey/releases/tag/7.2.14
- github.com/valkey-io/valkey/commit/98465eaffe3f95524a5046318bfbc4bdb9798291
- github.com/valkey-io/valkey/releases/tag/9.0.5
- github.com/valkey-io/valkey/releases/tag/8.1.9
- github.com/valkey-io/valkey/commit/06bc7768fe609f2054e69ccedefe7628f5675da9
- github.com/valkey-io/valkey/commit/e95911d4d65be8789fa3705f44d7ed1e65378445
- github.com/valkey-io/valkey/releases/tag/9.1.1
- github.com/valkey-io/valkey/commit/509cb3c74e8cbc9c0498ebe8b6c93dcd605e7271
- github.com/valkey-io/valkey/releases/tag/8.0.10
- github.com/valkey-io/valkey/commit/f8d2027e8d4df790ac04974bf606408c8ea62778
- github.com/valkey-io/valkey/pull/4073
- github.com/valkey-io/valkey/security/advisories/GHSA-mvcj-73cw-22m4
Elsewhere on this site
Related CVEs (same products)
- Low CVE-2026-86227 valkey-io valkey kvstore.c kvstoreGetHashtable out-of-bounds Sep 6, 2026
- Medium CVE-2026-85522 valkey-io valkey Slot Migration cluster_migrateslots.c createSlotImportJob out-of-bounds Sep 4, 2026
- Low CVE-2026-82677 valkey-io valkey Module Timer module.c moduleTimerHandler double free Aug 31, 2026
- Low CVE-2026-82631 valkey-io valkey Blocked-on-keys blocked.c handleClientsBlockedOnKey use after free Aug 31, 2026
- High CVE-2026-56684 Valkey: TLS pending-data processing use-after-free may allow remote code execution Aug 18, 2026
- High CVE-2026-27623 Valkey has Pre-Authentication DOS from malformed RESP request Feb 23, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-63639 is "Valkey: UAF in stream deserialization may lead to remote code execution", rated High. It affects Valkey (Valkey-io); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. EPSS 1.17% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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